Human cerebral cortical cell lines from patients with unilateral megalencephaly and Rasmussen's encephalitis

Continuous cerebral cortical cell lines have been developed from two patients, an 11-month-old with unilateral megalencephaly and a seven-year-old with Rasmussen's encephalitis, designated HCN-1 and HCN-2, respectively. The two cell lines stain for neuronal markers such as neurofilament and neuron-specific enolase but not for non-neuronal markers such as glial fibrillary acidic protein and S-100 protein. In the presence of appropriate growth factors, the cells extend long, branched processes resembling neurons. Differentiation of HCN-1 cells can be induced with nerve growth factor, dibutyryl cyclic AMP and isobutylmethylxanthine, while for HCN-2 cells nerve growth factor, isobutylmethylxanthine and the phorbol ester 12-O-tetradecaoylphorbol-13-acetate are most effective. Immunohistochemical staining of both differentiated cell lines reveals intense staining for GABA, glutamate, somatostatin, cholecystokinin-8 and methionine enkephalin. Two human cortical neuronal cell lines have been developed which represent neuronal precursors. These cell lines propagate in culture and are capable of differentiating upon the addition of a variety of growth factors and chemical agents. These cell lines should prove to be useful models for the study of in vitro neuronal processes.